Process of discharging halogen indigoes.



Patented May 24, 1904.

UNITED STATES PATENT OFFICE.

ARMAND JULIUS STIEGELMANN AND KARL .REINKING, OF LUDWIGS- HAFEN-ON -THE-RHINE, GERMANY, ASSIGNORS TO BADISCHE ANILIN UND SODA FABRIK, OF LUDWIGSHAFEN-ON-THE-RHINE, GERMANY, A CORPORATION OF BADEN.

PROCESS OF DISCHARGlNG HALOGEN INDIGOES.

SPECIFICATION forming part of Letters Patent No. 760,817, dated May 24, 1904.

Application filed February 26, 1904' To all whom it may concern:

Be it known that we,ARMAND JULIUS Strin- GELMANN, a subject of the German Emperor, and KARL REINKING, a subject of the Prince Regent of Brunswick, both doctors of philosophy and chemists, residing at Ludwigshafenon-the-Rhine, in the Kingdom of Bavaria, Empire of Germany, have invented new and useful Improvements in Processes of Discharging Halogen Indigoes, of which the following is a specification.

Our invention relates to the discharge of halogenated indigo coloring-matters.

It is well known that although ordinary indigo can be discharged by the use of theusual oxidizing agents, (such as chromates, chlorates, and bromates,) yet these agents of themselves have not the power of completely discharging halogenated indigo. We have now discovered, however, that halogenated indigo can be discharged to a sufiicient degree by employing an oxygen-carrier mixed with the oxidizing agent. Suitable oxygen -carriers for the purpose are, for example, soluble compounds of bismuth, antimony, magnesium,.

mercury, cobalt, arsenic, and arsenic acid, and also salts of vanadinic acid, nitric acid, arsenious acid, arsenic acid, and ferricyanic acid. It is a characteristic of the. action of these compounds that a very small quantity thereof is sufficient to produce the desired effect and that any excess beyond the necessary quantitydoes not increase the discharging power..

The following example will serveto further illustrate our invention, which, however, is in no way limited to this example. The parts are by weight: Print upon the material, which has been previously dyed to a medium shade with halogenated indigo, a discharging paste prepared by dissolving sixty (60) parts of an alkali bichromate and ten (10) parts of the double salt of antimony fluo'rid and antimony sulfate in two hundred (200) parts of water and adding to the solution seven hundred and thirty (730) parts of British gum thickening.

Instead of the above-mentioned antimony salt an equivalent quantity of another antimony salt or of another oxygen-carrier, such as one Serial No. 195,275.- (No specimens.)

thickening agent, and then drying, afterward subjecting the material to the action of dilute acid.

2. The process for the discharge of halogenated indigo coloring-matters, which process consists in printing upon the dyed material with a mixture of an oxidizing agent, an antimony salt, and a thickening agent, and then drying, afterward subjecting the material to the action of dilute acid.

3. The process for the discharge of halogenated indigo coloringmatters, which process consists in printing upon the dyed material with a mixture of an oxidizing agent, a double salt of antimony fluorid and antimony sulfate, and a thickening agent, and then drying, afterward subjecting the material to the action of dilute acid.

4:. The process for the discharge of halogenated indigo coloring-matters, which process consists in printing upon the dyed material with a mixture of an alkali bichromate, a double salt of antimony fiuorid and antimony sulfate, and athickening agent, and then drying, afterward subjecting the material to the action of dilute acid.

In. testimony whereof we have hereunto set our hands in the presence of two subscribing witnesses.

ARMANI) JULIUS STIEGELMANN. .KARL REINKING, Witnesses:

JAooB ADRIAN, ERNEST E. EHRHARDT. 

